Artificial leg.



G. B. MARTIN. 1

ARTIFICIAL LEG. APPLICATION FILED MAR. 15, 1911.

' 1,009,079. Patented N0v.21, 1911.

2 SHEETS-SHEET 1.

a, B. MARTIN. ARTIFICIAL LEG.

APPLICATION FILED MAR.15, 1911.

1,009,079. Patented N0v.21, 1911.

2 SHEETS-SHEET 2.

overcome this objection-and to so construct- UNITED STATES PATENT oFFToE.

CHARLES B. MARTIN, 013 DETROIT, MICHIGAN.

' ARTIFICIAL LEG;

To all whom it may concern:

Be it known that I, CHARLES B. MARTIN,

a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented new and useful Improvements in Artificial Legs, of which the following is a specification.

.This invention relates to artificial legs of the class which are provided with a suspender passing over the shoulders of the wearer and connected'with the pivoted lower section of the leg in such manner that the same is. swung forward when the wearer straightens his body or raises his shoulders, while being allowed to swing backward when he bends forward slightly 0r lowers his shoulders, as in the act of walking. The invention has more particular reference to artificial legs designed for cases where the amputation is above the knee. In artificial limbs of this kind, the knee-bolt or pivotal connection between the upper or thigh-section and the lower. or leg-section has heretofore been continuous or undivided from end to end and tapered more or less throughout its length. This construction is, however, objectionable, in that it allows the thigh-section to drift or shift toward the small endof the tapered knee-bolt, permitting the knee or lower portion of the thigh-section to come in contact with and rub against the inner top wall of the lower section. This causes squeaking and uneven wear of such contacting surfaces, rendering this construction annoying to the wearer and destructive to the leg.

One of the objects of my invention is to the knee-joint that it constantly tends to center the upper and lower leg-sections on each other.

A further object is to increase the strength and. durability of the connection between the Suspender and the lower legsection and render the same easy and reliable in action.

In the aocompanying'drawings consisting of 2sheets: Figure 1 1s a side elevation of an artificial leg embodying the invention. Fig. 2 is a front view and Fig. 3-a rear view of the same. Fig. 4 is a fragmentary longitudinal section of' the leg at right I angles to the knee-bolt, on an enlarged scale.

Fig. 5 is a fragmentary vertical section on line '55, Fig. 4:. Fig. 6 is a horizontal section on line 66, Fig. 4. Fig. 7 is a longitudinal section of the thigh-section of the Specification of Letters Patent.

Application filed March 15, 1911.

Patented Nov. 21, 1911.

Serial No. 614,598.

leg on line 7--7, Fig. 6. Fig. 8 is a perspective view of one of the retainers of the anti-friction rollers. Fig. 9 is a horizontal section'corresponding to Fig. 6, showing a modified construction of; the sectional knee-bolt and its operatingarm.

Similar letters ofreference indicate corresponding parts throughout the several views. A indicates the upper or thigh-sectionof the artificial leg and B the lower or legsection. The latter is provided with the customary internal straps C, C riveted or otherwise secured thereto and provided at their upper ends with the usual eyes 0, 0 extending above the top of the lower section. The thigh-section is provided in line with these eyes with the usual openings containing bushings cl of leather or other suitnaled. .This bolt instead of being continuous, is of divided or duplex construction.

In the embodiment shown in Figs. 18, the bolt consists of two sections E, E which are rigidly united at their inner ends by a coupling orsleeve F. In its preferred form, this sleeve is internally screw threaded and receives the reduced inner portions or threaded stems of the bolt-sections, as shown in Fig. 5. Both of'these bolt-sections are provided at their outer ends with heads which bear against the outer side of the strap-eyes c, and one of the sections, say the section E is provided adjacent to its head with a screw thread 6 which engages the correspondingly-threaded eye 0 while the other bolt-section and its corresponding .eye are unthreaded. A suitable locking dewith a notch h in the head of theknee-bolt section E, as shown in Figs. and 5.

As illustrated in Figs. 5 and 6', the two knee-bolt sections are tapered toward the center of the bolt and the bushings or bearings d have corresponding bores. By this construction, not only is a strong and tight joint secured, but the inwardly and oppositely tapering surfaces of the bolt-sections and the bushings insure the centering of .-the thigh-section upon the lower; or leg-.

I tapered from end to end. The joint is thus rendered more durable as well as practically noiseless.

I indicates an operating arm formed on or secured to the coupling sleeve F and extending forwardly therefrom. At its free front end this arm preferably carries one or more anti-friction rollers j mounted upon a cross pin is of the arm. Looped around these rollers is a pair of straps or cords L which pass through openings m, m in the front and rear sides of the thigh-sections and through corresponding guides n, a secured to the upper portion thereof. The upper ends of these straps terminate in rings 0 or other suitable attachments which in practice are connected with the front and rear members of theusual Suspender-which forms no part of the present invention and is therefore not shown in the drawings.

The rollers j are held upon the end portions of the cross pin 71: by retainers or plates 79, provided near their outer ends with screw threaded openings 22 which engage threads on the end-portions of said pin,

holding said plates against lateral displacement on the pin and confining the rollers between the plates and the operating arm I. The inner ends of the retaining plates p interlock with the adjacent sides of the knee bolt sections E, E the same being preferably provided for this purpose with curved notches or recesses p conforming to said sections. By this construction, the retaining plates areheldagainst turning on the screw threaded ends of the cross pin is. In assembling the 'parts just described, therollers are firstplaced upon the cross pin, the retaining plates are next screwed upon said pin and the knee-bolt sections are finally screwed into the coupling sleeve F.

9 indicates a back check of any suitable construction for limiting the forward swing of the lower leg-section.

In the use of the leg, straightens his body and strains the suspender, the cords L pull the operating arm I forwardly and upwardly, thereby turning the knee-bolt in the same direction and swinging the lower leg-section from its rear or deflected position to its straightened position shown in the drawings. When the wearerflbends forward slightly or lowers his shoulders, the suspender is relaxed, permitting the operating arm I and the lower leg section connected therewith through the knee-bolt to swing backward to its deflected position. This improvement thus gives the wearer practically complete control over the when tlie 'wearer lower leg-section, enabling him to walk naturally either slow or fast, and preventing his tripping when walking in snow or grass or upon uneven surfaces.

If desired, the construction of the duplex or double-taper knee-bolt may be changed or modified without departing. from the scope of the invention. For example, as shown in Fig. 9, the coupling sleeve F of the first described construction may be omitted and the operating device of the sectional knee-bolt E may consist of a double or bifurcated arm I, the members of which are respectively-secured to the inner ends of said bolt-sections. In this modification, the members of said operating arm are tied together by a cross pin or rivet 1', and a single antifriction roller 8 mounted on a second rivet s is employed, both of the cords or straps L necting saidsections and tapered 'from both ends toward its center.

2. 'The combination of a thigh-section, a leg-section,a knee-bolt pivotally connecting said sections,'said bolt consisting of sepa rate sections tapered toward the center of the bolt and means connecting said bolt sections.

3. The combination of a thigh-section, a leg-section, a knee-bolt pivotally connecting said sections, said bolt comprising inwardlytapering sections, and an operating arm connected to the inner portions of said boltsections.

4. The combination of a thigh-section, a leg-section, a knee-bolt pivotally connecting said sections, said bolt comprising inwardlytapering sections provided at their inner ends with screw threads, and ascrew-threaded coupling-sleeve engaging both of-said bolt-sections and carrying an operating arm.

5.'The combination of a thigh-section, a leg-section, a knee-bolt pivotally connecting said sections and comprising a pair of sections journaled in bearings in the thigh-section and rigidlysecured to the leg-section, said bolt-sections and bearings being tapered toward the center of the bolt, and an op- .erating arm connected with said bolt-sections.

6. The combination of a thigh-section having bearings, a lower or leg-section provided at its upper end with eyes coinciding with said bearings, a centrally-divided kneebolt pivotally connecting said sections, the sections of said bolt being tapered toward the center thereof, one of the bolt-sections having a screw threaded connection with the adjacent eye, means on the lower leg-section for locking the other bolt-section against turning, and an operating arm connected with said boltssections.

said sections, an operating arm connected 'with said knee-bolt and provided with a screw threaded cross pin, .an antifriction roller mounted onsaid pin, and a retaining plate provided at its inner end with a notch CHARLES B. MARTIN; Witnesses:

JOHN H. S'mm, FRED. D. LORIMER.

Copies of this patent may be obtained for five cents eaeh, by addressing the Commissioner of Patents,

" Washington, D. C. 

